Asthma is the most common chronic illness of childhood, and despite current advances in therapies, morbidity and mortality continue to increase. Low-income, minority teenagers have disproportionately high rates of asthma morbidity, including excess risk of emergency department care, hospitalization, and death from asthma, compared to white adolescents. Although urban children suffer the largest burden from asthma, they are the least likely group to receive adequate preventive care, and poor adherence plays a significant contributing role in asthma morbidity. Inner city adolescents with asthma are at particular risk of nonadherence. Thus, there is a substantial amount of suffering that could be prevented with improvements in care. This application builds on our extensive experience with efficacious school-based programs for urban children and teens with asthma. The overall goal is to broadly disseminate a novel system of asthma care throughout the entire city school district ('School Based Asthma Care for Teens'; SBACT), and test its effectiveness in improving adherence and reducing morbidity among urban teens. The SB-ACT intervention includes two core components. First, adolescents visit the school nurse daily for 6-8 weeks at the start of the school year to receive a trial of directly observed therapy (DOT) of preventive asthma medications. The goal is for the teen to establish a relationship with the nurse, learn proper medication technique, and experience the benefits and value of daily preventive therapy. Four to 6 weeks after the initiation of DOT, the teen will receive a motivational interviewing (MI) counseling program designed to enhance the teen's motivation to transition to independent, sustained preventive medication use. We will train community-based nurses affiliated with the local American Lung Association to deliver the MI component. The MI nurse will conduct three counseling sessions with the teen at school, which are designed to capitalize on the teen's experience with DOT and the potential benefits they experienced. Given the complex nature of asthma care in this population, we plan to evaluate this intervention using a 3-group design in which 430 teens will be randomly assigned to either; 1) the SB-ACT program (trial of DOT for 6-8 weeks + 3 MI counseling sessions); 2) DOT-only (DOT only for 6-8 weeks); or 3) an asthma education (AE) comparison group (in-school asthma education delivered by a trained asthma educator). We include the DOT-only group to evaluate whether this component alone is sufficient to promote sustained adherence without counseling. The AE group is designed to enhance asthma care and control for the attention received in MI counseling. We will assess the effectiveness of the SB-ACT intervention in reducing asthma morbidity, perform an economic sustainability analysis, and evaluate each component of program implementation with a focus on sustainability and dissemination. At the completion of the study, the effectiveness of this system of school-based asthma care will be better defined as a sustainable means to improve care for adolescents and reduce health disparities.